Few mode optical fiber

A few mode optical fiber comprising:

• a core region defined by a region around a central longitudinal axis of the few mode optical fiber, the core region comprising:
• a plurality of annular regions, wherein the plurality of annular regions comprising:
• a first annular region, wherein the first annular region is between the central longitudinal axis and a first radius r1, wherein the first annular region has a first refractive index delta-1;
• a second annular region, wherein the second annular region is between the first radius r1 and a second radius r2, wherein the second annular region has a second refractive index delta-2;
• a third annular region, wherein the third annular region is between the second radius r2 and a third radius r3, wherein the third annular region has a third refractive index delta-3;
• a fourth annular region, wherein the fourth annular region is between a third radius r3 and a fourth radius r4, wherein the fourth annular region has a fourth refractive index Δ4, wherein the fourth radius r4 is in a range of 8.3 microns to 9.9 microns and the fourth refractive index delta-4 is approximately zero;
• a fifth annular region, wherein the fifth annular region is between the fourth radius r4 and a fifth radius r5, wherein the fifth region has a fifth refractive index delta-5, wherein the fifth radius r5 is in a range of 10.9 microns to 12.6 microns and the fifth refractive index delta-5 is in a range of 0.41 to 0.62;
• and
• a cladding region, wherein the cladding region is a sixth annular region between the fifth radius r5 and a sixth radius r6, wherein the sixth annular region has a sixth refractive index delta-6, wherein the first annular region, the second annular region, the third annular region, the fourth annular region, the fifth annular region and the sixth annular region are concentrically arranged about the central longitudinal axis,
• wherein the few mode optical fiber has a spatial overlap between the Lp01 mode and Lp11 mode of less than 10−5.

A few mode optical fiber comprising:

• a core region defined by a region around a central longitudinal axis of the few mode optical fiber, the core region comprising:
• a first annular region, wherein the first annular region is between the central longitudinal axis and a first radius r1, wherein the first annular region has a first refractive index delta-1, wherein the first radius r1 is in a range of 3.8 microns to 4.2 microns and the first refractive index delta-1 is in a range of 0.42 to 0.70;
• a second annular region, wherein the second annular region is between the first radius r1 and a second radius r2, wherein the second annular region has a second refractive index delta-2, wherein the second radius r2 is in a range of 4.8 microns to 5.2 microns and the second refractive index delta-2 is approximately zero;
• a third annular region, wherein the third annular region is between the second radius r2 and a third radius r3, wherein the third annular region has a third refractive index delta-3, wherein the third radius r3 is in a range of 8.2 microns to 8.7 microns and the third refractive index delta-3 is in a range of 0.4 to 0.58;
• a fourth annular region, wherein the fourth annular region is between the third radius r3 and a fourth radius r4, wherein the fourth annular region has a fourth refractive index Δ4, wherein the fourth radius r4 is in a range of 8.3 microns to 9.9 microns and the fourth refractive index delta-4 is approximately zero;
• a fifth annular region, wherein the fifth annular region is between the fourth radius r4 and a fifth radius r5, wherein the fifth region has a fifth refractive index delta-5, wherein the fifth radius r5 is in a range of 10.9 microns to 12.6 microns and the fifth refractive index delta-5 is in a range of 0.41 to 0.62;
• and
• a cladding region, wherein the cladding region is a sixth annular region between the fifth radius r5 and a sixth radius r6, wherein the sixth annular region has a sixth refractive index delta-6, wherein the sixth radius r6 is 62.5 microns and the sixth refractive index delta-6 is approximately zero, wherein the first annular region, the second annular region, the third region, the fourth region, the fifth region and the sixth annular region are concentrically arranged about the central longitudinal axis, and
• wherein the few mode optical fiber has a spatial overlap between the Lp01 mode and Lp111 mode of less than 10−5, and
• wherein the first annular region has an alpha profile, wherein the alpha profile is defined by a peak shaping parameter alpha, wherein the peak shaping parameter alpha is in a range of 2.7 to 10.